
ProASIC3 DC and Switching Characteristics
2-22
Revision 13
Table 2-24 Summary of I/O Timing Characteristics—Software Default Settings
–2 Speed Grade, Commercial-Case Conditions: TJ = 70°C, Worst Case VCC = 1.425 V,
Worst-Case VCCI (per standard)
Advanced I/O Banks
I/O Standard
D
rive
S
tre
ng
th
Equiv
.Sof
tware
Default
Dri
v
eS
tre
ng
th
Opt
ion
1
Slew
Rate
C
ap
a
citive
L
o
a
d
(pF
)
Ex
tern
al
Re
sistor
(
)
t DO
UT
(ns)
t DP
(ns)
t DI
N
(ns)
t PY
(ns)
t EOUT
(ns)
t ZL
(ns)
t ZH
(ns)
t LZ
(ns)
t HZ
(ns)
t ZL
S
(ns)
t ZH
S
(n
s)
Un
it
s
3.3 V LVTTL /
3.3 V LVCMOS
12 mA 12 mA High 35
– 0.45 2.64 0.03 0.76 0.32 2.69 2.11 2.40 2.68 4.36 3.78 ns
3.3 V LVCMOS
Wide Range2
100 A 12 mA High 35
– 0.45 4.08 0.03 0.76 0.32 4.08 3.20 3.71 4.14 6.61 5.74 ns
2.5 V LVCMOS
12 mA 12 mA High 35
– 0.45 2.66 0.03 0.98 0.32 2.71 2.56 2.47 2.57 4.38 4.23 ns
1.8 V LVCMOS
12 mA 12 mA High 35
– 0.45 2.64 0.03 0.91 0.32 2.69 2.27 2.76 3.05 4.36 3.94 ns
1.5 V LVCMOS
12 mA 12 mA High 35
– 0.45 3.05 0.03 1.07 0.32 3.10 2.67 2.95 3.14 4.77 4.34 ns
3.3 V PCI
Per
PCI
spec
–
High 10 25 4 0.45 2.00 0.03 0.65 0.32 2.04 1.46 2.40 2.68 3.71 3.13 ns
3.3 V PCI-X
Per
PCI-X
spec
–
High 10 25 4 0.45 2.00 0.03 0.62 0.32 2.04 1.46 2.40 2.68 3.71 3.13 ns
LVDS
24 mA
–
High
–
– 0.45 1.37 0.03 1.20
–
ns
LVPECL
24 mA
–
High
–
– 0.45 1.34 0.03 1.05
–
ns
Notes:
1. The minimum drive strength for any LVCMOS 3.3 V software configuration when run in wide range is ±100 A. Drive
strength displayed in the software is supported for normal range only. For a detailed I/V curve, refer to the IBIS models.
2. All LVCMOS 3.3 V software macros support LVCMOS 3.3 V wide range as specified in the JESD-8B specification.
3. For specific junction temperature and voltage supply levels, refer to Table 2-6 on page 2-6 for derating values. 4. Resistance is used to measure I/O propagation delays as defined in PCI specifications. See Figure 2-10 on page 2-63 for connectivity. This resistor is not required during normal operation.